长白山地区红松树干呼吸的研究

Stem respiration of Pinus koraiensis in Changbai Mountains.

采用土壤呼吸气室于2003年5～10月测定了长白山阔叶红松林主要树种红松不同径阶不同方位的树干呼吸,同时监测了树干温度和林内温度.结果表明,树干呼吸速率具有明显的季节变化趋势,呈单峰曲线,8月出现最大值,2月呼吸速率最低.树干呼吸速率与树干温度具有显著幂指数关系,同时表现出大径阶树干呼吸速率与温度因子间曲线拟合效果好于小径阶红松.不同径阶树干呼吸速率均呈南面高于北面,并随树干径阶的减小南北面呼吸速率差异降低.不同径阶红松树干平均维持呼吸占总树干呼吸6363%,红松树干径阶越大维持呼吸所占比例越大.依树干径阶大小顺序分别为6676%、7329%和5084%.不同径阶红松树干呼吸Q10值在256～332之间,利用呼吸Q10值分别获得不同径阶树干Rt和Rm的季节变化趋势.因此,当估算生态系统呼吸时应考虑树干不同部位和不同径阶之间的差异.

In this paper,soil respiration chamber,a simple and precise method,was used to measure the stem respiration of trees.LI-6400-09 respiration chamber serving as a system is usually used in soil respiration,but we made polyvinyl chloride (PVC) collar and fixed it on the stem surface to measure the stem respiration.From May to October 2003,the stem respiration of Pinus koraiensis,the dominant tree species in Changbai Mountain,was measured in different time and different places using this technique.Meanwhile,the temperatures in the stems and in the forests were measured.The results showed that the stem respiration rate had a remarkably seasonal tendency with a single peak,the maximum was in August and the minimum was in February.The stem respiration rate had an exponential relationship with stem temperature,and the curve exponential regressions for stem respiration rate and temperature factor of trees with big DBH were better than those with small DBH.The stem respiration in different DBH trees was higher in the south stem face than that in the north stem face,and the variance of respiration rate between south and north decreased with a decrease of DBH trees.During the growing season from May to October,the average maintenance respiration accounted for 63.63% in different DBH trees,and the maintenance respiration contribution to total respiratory consumption increased with increasing DBH,which was 66.76,73.29% and 50.84%,respectively.The tem respiration Q_~10 values ranged from 2.56～3.32 in different DBH of trees,and the seasonal tendency for stem R_t and R_m in different DBH of trees was obtained by using respiration Q_~10 .Therefore,the differences between different parts of stem and different DBH of trees should be considered in estimating the respiration model in ecosystem.